Biomaterials for spinal cord regeneration: Outgrowth of presumptive neuronal precursors on electrospun poly(ε)-caprolactone scaffolds microlayered with alternating polyelectrolytes

The aim of this study was to assess the feasibility of electrospun poly(ε)-caprolactone (PCL) scaffolds treated with alternating paly-electrolytes as a controllable three-dimensional adhesive substrate for neuronal progenitors. Unmodified PCL surfaces were generally not supportive of mouse embryonic stem cell (mESC) colony adhesion. However, scaffolds surfaced using layer-by-layer (LbL) deposition of heparin/poly-L-lysine encouraged better local adhesion of mESC colonies, and networking of monolayers containing nestin-positive presumptive neurons, similar to laminin coated controls, as observed by immuno-fluorescence microscopy. Confocal microscopy further revealed depth-wise penetration of mESC nestin-positive cell populations, and orientation along grass topographical features in the LbL scaffolds. LbL deposition therefore appears to provide a satisfactory adhesive substrate for contact and mechanical guidance of neuronal outgrowth in three-dimensions.